Expansible reamer



M. l. vSEILEF:

Jan. 3, 1928.

.IIIIIIIIIIIIIIII Patented Jan. 3, 1928 UNiTED STATES PATENT ol-fl-"Icav MICHAEL I'. sErLER, '0F M-ILLERS'BURG; raNNs'YLvANIA.

nxPANs'InnE naman,

. Application med Mami 1925. Y serial No. ias.

This invention relates to expansible reamers. l y v The object is to provide a toolof this class, equipped with the usual spirally-arranged cutting elements, which are produced entirely by machining processes inl order yto4 secure the great degree Vofwaccuracy neces sary to obtain the best results infine. work; such `tools being ordinarily formed by'a heatingrand twisting process which canl not be relied upon .for the desired accuracy. l

Y Another object is to provide a reamerhaving such spiral elements formed on expansible sections integrally joined together to give the greatest strength and rigidity, said sections being readily expanded yby a simple operation and adapted to automatically resume their normal relation to each other when desired, the expansion having no effect on the cutting element-s exceptto render the device capable of reaming aclarger hole orbore.

In carrying out these objects, Iprovide an having a yplurality of' raf. .dially-eXtend-ing, spirally-formed .cutting flutes or flanges, suitably bevelled or backed off to provide the necessary edge, and each iiute having its forward end tapered to provide a first or initial point of attack on thel metal to be removed inf the expansible reamer reaming process, and also havingfa'secondy point of metal attack at lor near the center,

which'has the .greatest diameter when thev reamer is eXp'a-nded.

A full and complete understanding of the invention may be obtained from a considera.

tion of theV following detailed description,

taken in connection with the accompanyingV drawing forming 'a *part of thisv specification; it being understood that while Vthe drawing` shows al practicaljiform ofvthejinvention, the latter is not vto be confined to 'strict conformity with. thefshowingthereof,

but may be changed orimodiliedg'so long as such changes or modificationsmark no material departure from the salienty features of the invention as. specifically 'pointed out iny the appended claims. Y' v In thev drawing, in which similar reference characters vdesignate corresponding 'partsthroughout the several figures:`

tionP .ly .is a side elevation of a reamer .-Eigure `2V is allongitudinal sectional view of the-same. l i i `Figurer?) is a thereof, and A u f Vliiguree'is4v a `detail section taken longitudinally ofone of the lspira-l 1cutting flutes. The vimproved reamer is formed of, a sin-v gle piece of `suitable barjmetal, preferably the best grade of tool steel, the same being round in cross section and of a diameter" suitable to the size of the reamer to beproduced. At onev end, constitutingthe shank end l of the reamer, vsaid bar is formed into a rectangular` portion 2 for securing the tool inaturning head in the usual manner. l,

transverse vsectional View In` proper spaced relation to the Asquared j gitudinal axis of the sameA to al pointsubfy stantially midway between fthe@ aforesaid channels 3 yand 4, orthe center of the body'.l

The said bore here communicates with a smaller bore`7 which extends into the shank lof the reamer, theA two bores being oined together by a'4 tapered shoulder 8,.` i,

The inner shoulders l9 and 10 of the` chan-y nels 3 and 4 respectively, are preferably bevelled' back towards the center Aof the body as shown, and between these two points ase- 'rics of spiraltlutes 1:1 are formed .by suitably `machining the bar whilewthe latter is giventheproper amount oftwist ltocarry the" cutting Atool ,substantially half .way around the .body ofthe tool, the 'outer active or Lcutting'edge of 131.1@ flutes being of the normal diameterv ofthe bar. l e i v. l. v In) a ri'glit-,handA reamer (as showny in; the

` drawing) the .Spiral .flutaS,11.St-atttbe i111 ner channel .3?. andrxtld.halffwaydlfllnd the body from right 4to v left and where@ left hand reamerl 'is ftolbe;A made, .theflutes extend in the opposite directionf` Y R TheV clon# .gated cuts or, grooves made to .formther'yfll'a'sl` have one wall .extending subwstntally .pei-.- Y

pendicular to the axis of the reamer, while the other wall is formed on a curve extending out to the ad]acent edge ofthe next flute, said cuts or grooves extending into the `12 will perform its function of entering and removing the metal from the holeior bore being roamed, andateach end the flutes are tapered inwardly, as shown at 13, the front tapers serving to cause the tool to enter the work and constituting the first point I of metal attack.

As' thus far described the structure constitutes a non-expansible spiral reamer suit-` able for use in many cases, and in order to have the added advantage of exvpansibility the body of the reamer is provided with a plurality of radially-disposed slits lll, extending from the central bores 6 and? to the outer face of the reamer, and intersecting the several flutes at an angle as a consequence of the spiral form of the flutes. Theslits 14' are formed perfectly straight and exactly radial to the longitudinal axis of Jthe reamer, and

' the same are very narrow so as 'not to form any material interruption to the continuity of the flutes. The slits forma series of sections in thev body of t-he reamer which are adapted to be centrally expanded by means to be described.

The peripheries of the cutting flutes are nowA planed or ground `off where traversed by the slits to provide flat surfaces thereon, said surfaces being exactly perpendicular to the radial slits and extending equal 'distances at either sidc'of the same. The'surfaces 15 of the flutes along` any one of the slits are all on the same plane, andl forn'nfin effect, tapere'd ends to each section of each flute on each expansible sectionv of the reamer, in muchthe same manner as the tapered' ends 1 3 at theterininals of the flutes, and as the reainer is turned these flatportions 15 will constitute a second point of metal attack for cutting into and removing the metal in the process of roaming. Y i

Villien the reainer is expanded for use i n a larger bore or hole, or when a larger amount 1 of .rnetalis to be removed, the greatest 'dianieter is located midway between the channels 3 and 4; as the sections of the reamer, as

Vdefined between the slits, arevforced radially outward from theaxis thereof, and it will be seen that the tapered vends 13 at the front or head end of the reamer, together with the fiat portions 15 located between the front end 13 and the center, will be forced to? do the work of attacking the metal, as the reamer is forced through while turning to the right,V

the following flat surfaces 15 being of gradually reducing diameter.

A steel pin 16 round in'eross section and o a diameter to .freely slide into the outer, larger bore 6 is fitted into the same, and is provid ed with a tapered inner end 17 to engage the aforesaid tapered shoulder 8, through the mediiun of which, when the pin is advanced into the bore, the sections comprising the body of the reamer'are forced radially outward in an obvio-us manner.

Thev outer end portion of the pin is provided with screw threads 18, which engage the internal threads 19 of the bore 6', and the outer terminal ofthe pin is flattened as at 20 to facilitate turning the same to advance into the bore and expand the reamer.

It has been found in practice that the besty results are obtained by forming eight equally spaced flutes halfway roundthe body of thek reamer, and to intersect the same by forming three slits, such -arrangement providing a staggered relation between the several flat surfaces 15 on the different flutesv and causing a. more constant attack on the metal, and amore uniform pull or feed on the reamer, with a less expenditure of force or labor. A different number of flutesy and slits may, however, be employed.

From the foregoing it will be seenthat a machine made tool of great accuracy has been provided, which may be used for expediting the process of reaming bores, etc., said 'tool having a plurality of roaming flutes, each of which is provided with a. plurality of `points for' attaching the metal or starting the cut, such points being in spaced and staggered rela-tion to each other to cause the tool to advance more rapidly and to remove the metal more effectively, either' when expanded or whenin normal contracted condition. i. What is'claimed is:V Y

1. An expansible reamer comprising a body round in cross section and having al boreA extendingffrom one end to near the other endr thereof,a series of outstanding equally spaced fiutesformed on the exterior lof the body, said flutes extending througll out the length r.of the body and arranged spi-rally thereon to extend substantially half way round the saine, the forward edge of each flute being formed intoa cuttil'ng;V edge for roaming a bore, saidflutes at their front ends being` bevelled-toform a first point vof metal-attack, said body being divided into a plurality of integrally! connected elonf gated, radially expa-nsible sections by straight, radially-disposed longitudinal slits extending throughout ythe length Vof the body, and 'intersecting a plurality 'of rthe flutes.

2. An expansible reainer comprising a' round'body memberhaving a longitudinal bore and provided with exterior, spirally arranged. ribs or flutes,I eachl flute being `bevi,-`

thereto, each section provide :La arranged ribs v elled to provide a forward cutting edge, the

55 thereto, the

elled to provide a forward cutting edge, the

front end of each flute being tapered to x equally-spaced, radially-disposed, longitudinal slits, extending into the central longitudinal bore, said sect-ions being integrally joined together at their ends, each slit intersecting a plurality of the ribs at an angle having its several flute portions tapered at theends to form additional points of metal-attack.

3. An expansible re'ainer comprising a round body member having a longitudinal bore and provided with exterior, spirallyarranged i'ibs or flutes, each flute being bevelled to provide a forward cutting edge, the.

front end of each flute being tapered to form a first point of metal-attack, said body '"f" being divided into expansible sections by equally-spaced, radially disposed, longitudi-` nal slits, extending into the central longitudinal bore, said sections being integrally goined together at their ends, each slit intersecting a plurality of the ribs at an angle thereto, the flutes being provided in their peripheries with flat portions arranged perpendicular to the slits and extending an equal distance on either side of the saine to second points of metal-attack on each flute.

Ll. An expansible reamer comprising a round body member having a 'longitudinal bore and provided with exterior, spirallyor flutes, each flute being bevfront end of each'flute being tapered to forni a first point of being divided into expansible sectionsfby equally-spaced radially-disposed, longitudinal slits, extending in to the central, longitudinal bore, said sections being integrally l joined togetheryat their ends, eaehslit intersecting a plurality of the ribs'at anv angle body member being exteriorly planed or ground `longitudinally of its length to provide flat planes perpendicular to the radial slits and form, in effect, downwardly-tapered ends to each of the flute secf metal-attack, said bodyv tions to act as additional points of metal attack progressively arranged around the reamer. Y p 5. An expansible reamer comprising a round body member having a longitudinal bore and provided with exterior, spirallyarranged iibs or flutes, each flute being bevelled to provide a forward cutting edge, the

Afront end of each flute being tapered to forni a first point of metal-attack, said body being divided into expansible sections by equally-spaced, radially-disposed, longitudinal slits extending in to the central, longif tudinal bore, said sections being integrally to said slits to constitute additional metal'- attackiiig points:

'6. An expansible reamer comprising an elongated body member having an inter- .nal bore, said body having a plurality of straight, longitudinal slits to provide outwardly expansible sections integrally joined together at their ends, a plurality of spirally-arranged cutting flutes formed exterioily on the bodypmember, said flutes being intersected by said slits, and. each flute being tapered at its front end to provide a first metal-attacking point' and also tapered at each intersection to provide metal-attacking points. y

7. An expansible reamer comprising an elongated body having a plurality of outstanding, spirally-arranged cutting flutes, each flute having a metal-attacking point at the front end, and arsecond metal-attacking point intermediate of its ends, said body additional being longitudinally slittedk to provide ex- *I pansible sect-ions integrally-connected toture.

` MICHAEL I. SEILER.

' 90` gether at each end, said slits intersecting 

